Stresses in Laminated Composites Containing a Broken Layer

Abstract

The stresses are determined around a crack in bimaterial laminated composite with elastic constituents. The crack is created by a broken layer and has a finite length. The solution presented in this paper applies to the problem where either the normal displacement or the normal stress can be prescribed. For the case when the normal stress is prescribed, a singular differential-integral equation is derived which the normal displacement of the crack surface must satisfy. A set of composite parameters is used which provide some pertinent information for this crack problem. To obtain numerical results a method which may have general application is used to reduce a singular differential-integral equation to a tractable form for computations. The results indicate that, as the ratio of shear modulus of the broken layer to shear modulus of adjacent material becomes large, the stresses which result from the presence of the crack lend to concentrate around the crack tips. Estimates of the stress-intensity factor which may be obtained without extensive numerical computation are also discussed.